Currently, bath chairs are provided for taking care of an infant in a bathroom. These bath chairs comprise a seat having a protrusion at a front center part, a seat back having a reclining mechanism, and a handle provided from side to side above a front side of a seat. Heretofore, various proposals have been made on structures of the reclining mechanism.
For example, Japanese Patent No. 5140839 describes a bath chair that includes a retractable engaging rod at both lower left and lower right sides of a backrest. A base is provided with a plurality of rod holes for engaging with the engaging rod. A pair of operating members for retracting and protruding the each left and right engaging rods is provided to an upper part of a back side of the backrest where respectively correspond to the each left and right engaging rods. The operating member and the engaging rod are connected by an engaging member which is formed extending to perpendicular direction. The engaging member is biased toward a direction in which the engaging rod protrudes. In order to perform a reclining operation, the pair of operating members is pinched against bias force of the engaging member so as to retract the engaging rod. Next, an inclination angle of the backrest is changed with the operating members pinched (engaging rods retracted, in other words) so that the engaging rod aligns with a desired rod hole. By releasing the pinched operating members at the inclination angle in which the engaging rod aligns with the desired rod hole, the engaging rod protrudes to engage with the desired rod hole, whereby the backrest is fixed.
A reclining mechanism described in Japanese Patent No. 5140839 has a certain perpendicular distance between the operating member and the engaging rod. Accordingly, when the pair of operating members is pinched in order to retract the engaging rods, rotational force is generated around a position where a lower portion of the operating member intersects with an axis line of the engaging rod, and is applied to the connecting member for connecting the engaging rod and the operating member. The rotational force makes parallel movement of the engaging member in lateral direction difficult, although the connecting member should move parallel in lateral direction. This interferes with transmission of a pinching force on the operating members to elastic members directly. Consequently greater force is required for retracting the engaging rods relative to elastic force of the elastic member; hence the reclining operation cannot be performed easily with one hand.